Method for gas phase reactant catalytic reactions

Abstract

The present invention provides chemical reactors and reaction chambers and methods for conducting catalytic chemical reactions having gas phase reactants. In preferred embodiments, these reaction chambers and methods include at least one porous catalyst material that has pore sizes large enough to permit molecular diffusion within the porous catalyst material.

We claim:  
     
       1. A method of hydrocarbon steam reforming comprising: 
       passing a reactant stream comprising steam and hydrocarbon into at least one reaction chamber;  
       said reaction chamber having an internal volume wherein said internal volume has dimensions of chamber height, chamber width and chamber length;  
       wherein said at least one reaction chamber comprises a chamber height or chamber width that is 2 mm or less;  
       wherein said at least one reaction chamber has a beginning and an end and wherein said chamber length is the distance from the beginning to the end of the reaction chamber;  
       wherein said reactant stream entering the beginning of the reaction chamber is converted to a product stream exiting the reaction chamber;  
       said product stream comprising hydrogen, carbon dioxide and carbon monoxide;  
       wherein the hydrocarbon in the hydrocarbon steam reforming has an equilibrium conversion;  
       wherein at least 70% of said equilibrium conversion of the hydrocarbon entering the beginning of said at least one reaction chamber is converted to hydrogen, carbon monoxide and/or carbon dioxide; and  
       wherein said hydrocarbon has a contact time of less than 300 milliseconds.  
     
     
       2. The method of  claim 1  wherein the reaction chamber comprises a porous catalyst material and a bulk flow channel. 
     
     
       3. The method of  claim 2  wherein the bulk flow channel is contiguous from the beginning to the end of the reaction chamber. 
     
     
       4. The method of  claim 2  wherein there are multiple bulk flow channels within said reaction chamber. 
     
     
       5. The method of  claim 2  wherein there is a pressure drop from the beginning to the end of the reaction chamber that is less than 20%. 
     
     
       6. The method of  claim 2   
       wherein the hydrocarbon comprises methane;  
       wherein the methane in the hydrocarbon steam reforming has an equilibrium conversion;  
       wherein at least 90% of said equilibrium conversion of the methane entering the beginning of said at least one reaction chamber is converted to hydrogen, carbon monoxide and/or carbon dioxide; and  
       wherein the methane has a contact time of less than 30 milliseconds.  
     
     
       7. The method of  claim 6  wherein the reaction chamber comprises sides and at least two sides of said reaction chamber have a porous catalyst material. 
     
     
       8. The method of  claim 6  wherein the porous catalyst material has a pore volume of 5 to 95% and more than 20% of the pore volume comprises pores having sizes of from 0.3 to 200 microns. 
     
     
       9. The method of  claim 6  wherein the methane has a contact time of between 1 and 25 ms. 
     
     
       10. The method of  claim 6  wherein the porous catalyst material has a pore volume of 30 to 95%; and wherein at least 50% of the pore volume is composed of pores in the size range of 0.1 to 300 microns. 
     
     
       11. The method of  claim 2  further comprising a step of adding heat to the reaction chamber from an adjacent microchannel heat exchanger. 
     
     
       12. The method of  claim 11  wherein the heat exchanger comprises a heat exchange fluid flowing in cross current to said reactant stream. 
     
     
       13. The method of  claim 2  wherein the porous catalyst material has a pore volume of 30 to 95%; and wherein at least 50% of the pore volume is composed of pores in the size range of 0.1 to 300 microns. 
     
     
       14. The method of  claim 1  wherein the method of hydrocarbon steam reforming is conducted in an integrated device comprising at least 10 reaction chambers that are connected in parallel. 
     
     
       15. The method of  claim 1  wherein the chamber height or chamber width is 1 mm or less and the chamber length is greater than 1 cm. 
     
     
       16. The method of  claim 1  wherein the reaction chamber comprises a porous catalyst material having a pore volume of 5 to 98%; wherein at least 50% of the material's pore volume is composed of pores in the size range of 0.1 to 300 microns. 
     
     
       17. The method of  claim 16  wherein the hydrocarbon has a contact time of less than 100 ms. 
     
     
       18. The method of  claim 1  wherein the reaction chamber comprises an inlet and an outlet and a bulk flow path that is contiguous from the inlet to the outlet. 
     
     
       19. The method of  claim 18  wherein the bulk flow path comprises 30-80% of the cross-section of the reaction chamber. 
     
     
       20. The method of  claim 18  wherein the pressure drop from the inlet to the outlet is less than 20%. 
     
     
       21. The method of  claim 18  wherein the hydrocarbon has a contact time of between 1 and 25 ms. 
     
     
       22. The method of  claim 18  wherein the reaction chamber comprises a porous catalyst layer wherein at least 50% of the total pore volume is composed of pores in the size range of 10 −9  to 10 −7  in diameter, and comprising an active constituent selected from the elements in the IUPAC Group IIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IVB, lanthanide series and actinide series. 
     
     
       23. The method of  claim 18  wherein the reaction chamber comprises baffles that comprise a thermally conductive metal. 
     
     
       24. The method of  claim 23  wherein the baffles comprise a porous catalyst material. 
     
     
       25. The method of  claim 18  wherein the reaction chamber exchanges heat with a combustor and wherein the reaction chamber has a reaction chamber wall in contact with a combustor and wherein the combustor and reaction chamber have a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       26. The method of  claim 18  further comprising a continuous removal of products to drive the reforming reaction. 
     
     
       27. The method of  claim 18  further comprising a step of recycling a portion of the product stream back into a reaction chamber. 
     
     
       28. The method of  claim 27  further comprising a step of removing hydrogen from the product stream while on a recycle path back to an earlier reaction section. 
     
     
       29. The method of  claim 1  wherein the hydrocarbon has a contact time of less than 50 ms. 
     
     
       30. The method of  claim 1  wherein the reaction chamber contains two catalyst inserts, wherein the catalyst inserts comprise a porous catalyst material. 
     
     
       31. The method of  claim 1  wherein the reaction chamber comprises catalyst fibers. 
     
     
       32. The method of  claim 1  comprising a porous catalyst matrix material within which there 10 to 1000 contiguous bulk flow channels. 
     
     
       33. The method of  claim 1  wherein the reaction chamber comprises a bulk flow path and porous plug; wherein the porous plug comprises a porous catalyst material and wherein the porous plug is disposed in the reaction chamber such that gaseous reactants that remain unreacted after passage through the bulk flow path contact the porous plug. 
     
     
       34. The method of  claim 1  wherein the reaction chamber comprises a catalyst comprising a parallel pore structure. 
     
     
       35. The method of  claim 1  wherein the reaction chamber comprises a bulk flow channel and a porous catalyst having a porosity in the range of 30 to 98%. 
     
     
       36. The method of  claim 35  wherein the bulk flow channel is contiguous from the beginning to the end of the reaction chamber and wherein the porous catalyst has a pore size of 0.1 μm to 200 μm. 
     
     
       37. The method of  claim 1  wherein the reaction chamber comprises a porous support with a catalytic metal thereon and comprising an active constituent selected from the elements in the IUPAC Group IIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IVB, lanthanide series and actinide series. 
     
     
       38. The method of  claim 1  wherein the reaction chamber comprises a porous catalyst having a pore volume of 5 to 98% wherein at least 20% of the material's pore volume is composed of pores in the size range of 0.1 to 300 μm. 
     
     
       39. The method of  claim 1  wherein the reaction chamber is in thermal contact with a microchannel heat exchanger and wherein the combination of reaction chamber and microchannel heat exchanger have a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       40. The method of  claim 39  wherein the reaction chamber comprises a bulk flow channel that is contiguous from the beginning to the end of the reaction chamber; and wherein the reaction chamber comprises a catalyst comprising an active constituent selected from the elements in the IUPAC Group IIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IVB, lanthanide series and actinide series. 
     
     
       41. The method of  claim 40  wherein the catalyst comprises Rh. 
     
     
       42. The method of  claim 1  conducted in an integrated device comprising at least 10 reaction chambers and at least 10 microchannel heat exchangers wherein heat is transferred between the at least 10 reaction chambers and the at least 10 microchannel heat exchangers at a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       43. The method of  claim 1  wherein the reaction chamber is in thermal contact with a second reaction chamber in which an exothermic reaction is occurring and wherein the combination of the reaction chamber and the second reaction chamber have a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       44. The method of  claim 43  wherein the reaction chamber comprises a bulk flow channel that is contiguous from the beginning to the end of the reaction chamber; and wherein the reaction chamber comprises a porous catalyst comprising an active constituent selected from the elements in the IUPAC Group IIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IVB, lanthanide series and actinide series. 
     
     
       45. The method of  claim 43  wherein the exothermic reaction comprises combustion, and further comprising the steps of preheating the reactant stream before the stream passes into the reaction chamber. 
     
     
       46. A method of conducting a chemical reaction comprising: 
       passing a gaseous reactant into a bulk flow path of a reaction chamber;  
       said reaction chamber having an internal volume, defined by reaction chamber walls, wherein said internal volume has dimensions of chamber height, chamber width and chamber length;  
       wherein said at least one reaction chamber comprises a chamber height or chamber width that is about 2 mm or less;  
       wherein a porous catalyst material is disposed within said internal volume and in close contact with a reaction chamber wall, wherein said porous catalyst material has a porous internal structure such that the gaseous reactant can diffuse molecularly within the material;  
       wherein the gaseous reactant reacts in the porous catalyst material to form at least one product; and  
       wherein said bulk flow path is contiguous throughout said chamber length.  
     
     
       47. The method of  claim 46  wherein the porous catalyst material comprises a porous catalyst matrix material in which there are 10 to 1000 contiguous bulk flow channels. 
     
     
       48. The method of  claim 46  wherein the reaction chamber has reaction chamber walls and wherein the porous catalyst material is disposed within the reaction chamber without direct contact to the reaction chamber walls. 
     
     
       49. The method of  claim 46  comprising at least two reaction chambers and a mixing chamber that combines gases from the at least two reaction chambers. 
     
     
       50. The method of  claim 46  wherein the porous catalyst material has a pore volume of 30 to 95%; and wherein at least 50% of the pore volume is composed of pores in the size range of 0.1 to 300 microns. 
     
     
       51. The method of  claim 46  wherein the contact time of the gaseous reactant in the reaction chamber is less than 100 milliseconds. 
     
     
       52. The method of  claim 51  wherein the chemical reaction is selected from the group consisting of: acetylation, amination, arylation, dehalogenation, epoxidation, esterification, Fischer-Tropsch, halogenation, hydrohalogenation, hydrometallation, hydrosilation, hydrotreating (HDS/HDN), metathesis, nitration, sulfonation, and transesterification. 
     
     
       53. The method of  claim 51  wherein the reaction chamber contains two porous catalyst material inserts. 
     
     
       54. The method of  claim 51  wherein the bulk flow channel has a cross-section and wherein this cross-section comprises 30-80% of the cross-section of the reaction chamber. 
     
     
       55. The method of  claim 51  wherein the chamber height or chamber width is 1 mm or less and the chamber length is greater than 1 cm. 
     
     
       56. The method of  claim 55  wherein the contact time of the gaseous reactant in the reaction chamber is between 1 and 25 ms. 
     
     
       57. The method of  claim 51  wherein the reaction chamber is in thermal contact with a microchannel heat exchanger and wherein the combination of reaction chamber and microchannel heat exchanger have a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       58. The method of  claim 51  wherein the reaction in the reaction chamber is endothermic and wherein the reaction chamber is in thermal contact with a second reaction chamber in which an exothermic reaction is occurring and wherein the combination of the reaction chamber and the second reaction chamber have a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       59. The method of  claim 51  wherein the reaction chamber has an inlet and an outlet and wherein pressure drop from the inlet to the outlet is less than 10%. 
     
     
       60. The method of  claim 51  wherein at least 50% of the porous catalyst material's pore volume is composed of pores in the size range of 0.3 to 200 μm. 
     
     
       61. The method of  claim 60  wherein the chemical reaction is selected from the group consisting of Fischer-Tropsch reaction, dehydrogenation, hydrogenation, partial oxidation, alkylation, epoxidation, and water gas shift. 
     
     
       62. The method of  claim 51  wherein the reaction chamber contains a first type of catalyst and wherein the at least one product passes into a subsequent reaction chamber containing a second type of catalyst where the at least one product is converted into another product. 
     
     
       63. The method of  claim 51  wherein the chemical reaction is selected from the group consisting of: acetylation, addition reactions, alkylation, dealkylation, hydrodealkylation, reductive alkylation, amination, aromatization, arylation, autothermal reforming, carbonylation, decarbonylation, reductive carbonylation, carboxylation, reductive carboxylation, reductive coupling, condensation, cracking, hydrocracking, cyclization, cyclooligomerization, dehalogenation, dimerization, epoxidation, esterification, exchange, Fischer-Tropsch, halogenation, hydrohalogenation, homologation, hydration, dehydration, hydrogenation, dehydrogenation, hydrocarboxylation, hydroformylation, hydrogenolysis, hydrometallation, hydrosilation, hydrolysis, hydrotreating (HDS/HDN), isomerization, methylation, demethylation, metathesis, nitration, oxidation, partial oxidation, polymerization, reduction, reformation, reverse water gas shift, sulfonation, telomerization, transesterification, trimerization, and water gas shift. 
     
     
       64. A method of conducting a chemical reaction in a chemical reactor comprising: 
       passing a gaseous reactant into a first and/or second compartment;  
       wherein a partition is disposed between the first compartment and the second compartment;  
       wherein said partition comprises a fluid distribution layer;  
       wherein said first compartment has an internal volume;  
       wherein said internal volume has dimensions of compartment height, compartment width and compartment length;  
       wherein said first compartment comprises a compartment height or compartment width that is about 2 mm or less;  
       wherein said first compartment comprises a porous catalyst material;  
       wherein a gas travels through said partition; and  
       wherein said first compartment comprises at least one open space that permits bulk flow of a gas.  
     
     
       65. The method of  claim 64  wherein said second compartment comprises at least one open space that permits bulk flow of a gas; 
       wherein said gaseous reactant convectively travels through the flow distribution layer from the first to the second compartment;  
       wherein said gaseous reactant, after traveling through said flow distribution sheet, reacts in a porous catalyst material contained within the second compartment.  
     
     
       66. The method of  claim 64  wherein said chemical reactor comprises multiple reaction chambers arranged in parallel or in series; and 
       comprising passing a gaseous reactant into the first compartment of said multiple reaction chambers.  
     
     
       67. The method of  claim 64  wherein the porous catalyst material has a pore volume of 30 to 95%; and wherein at least 50% of the pore volume is composed of pores in the size range of 0.1 to 300 microns. 
     
     
       68. A method of conducting a chemical reaction in a chemical reactor comprising: 
       passing a gaseous reactant into a first and/or second compartment;  
       wherein a partition is disposed between the first compartment and the second compartment;  
       wherein said partition comprises a separating agent;  
       wherein said first compartment has an internal volume  
       wherein said internal volume has dimensions of compartment height, compartment width and compartment length;  
       wherein said first compartment comprises a compartment height or compartment width that is about 2 mm or less;  
       wherein said first compartment comprises a porous catalyst material;  
       wherein a gas travels through said partition; and  
       wherein said first compartment comprises at least one open space that permits bulk flow of a gas and is disposed between the partition and the porous catalyst material; and  
       wherein said second compartment comprises at least one open space that permits bulk flow of a gas.  
     
     
       69. The method of  claim 68  wherein said separating agent comprises a palladium membrane, and wherein said comprises continually removing hydrogen through the palladium membrane. 
     
     
       70. A method of conducting a chemical reaction in a chemical reactor comprising: 
       passing a first gaseous reactant into a first compartment of a reaction chamber;  
       wherein said reaction chamber comprises a porous catalyst material, a first compartment and a second compartment;  
       wherein said first compartment has an internal volume;  
       wherein said internal volume has dimensions of compartment height, compartment width and compartment length;  
       wherein said first compartment comprises a compartment height or compartment width that is about 2 mm or less;  
       wherein said porous catalyst material is disposed between said first compartment and said second compartment;  
       passing a second gaseous reactant into the second compartment of a reaction chamber;  
       wherein the second gaseous reactant reacts with the first gaseous reactant within said porous catalyst material to form at least one product; and  
       wherein said first compartment and said second compartment comprise open spaces that permit bulk flow of a gas; and  
       recycling at least a portion of the at least one product back into said reaction chamber.  
     
     
       71. The method of  claim 70  wherein said at least one product passes into the second compartment. 
     
     
       72. The method of  claim 71  wherein the first compartment comprises a compartment height or compartment width that is 1 mm or less, and 
       wherein said second compartment has a second internal volume wherein said second internal volume has dimensions of second compartment height, second compartment width and second compartment length;  
       wherein said second compartment comprises a compartment height or compartment width that is 2 mm or less.  
     
     
       73. The method of  claim 71  wherein said at least one product that passes into second compartment, enters the second compartment in a distributed manner along the length of the second compartment. 
     
     
       74. The method of  claim 73  wherein the chemical reaction is selected from the group consisting of: alkylation, epoxidation, Fischer-Tropsch, hydrogenation, dehydrogenation, partial oxidation, and water gas shift. 
     
     
       75. The method of  claim 73  wherein the open spaces in the first and second compartments each have a cross-sectional area of 5×10 −7  to 10 −4  m 2 . 
     
     
       76. The method of  claim 75  wherein the chemical reaction is selected from the group consisting of: acetylation, addition reactions, alkylation, dealkylation, hydrodealkylation, reductive alkylation, amination, aromatization, arylation, autothermal reforming, carbonylation, decarbonylation, reductive carbonylation, carboxylation, reductive carboxylation, reductive coupling, condensation, cracking, hydrocracking, cyclization, cyclooligomerization, dehalogenation, dimerization, epoxidation, esterification, exchange, Fischer-Tropsch, halogenation, hydrohalogenation, homologation, hydration, dehydration, hydrogenation, dehydrogenation, hydrocarboxylation, hydroformylation, hydrogenolysis, hydrometallation, hydrosilation, hydrolysis, hydrotreating (HDS/HDN), isomerization, methylation, demethylation, metathesis, nitration, oxidation, partial oxidation, polymerization, reduction, reformation, reverse water gas shift, sulfonation, telomerization, transesterification, trimerization, and water gas shift. 
     
     
       77. The method of  claim 70  wherein the porous catalyst material has a pore volume of 30 to 95%; and wherein at least 50% of the pore volume is composed of pores in the size range of 0.1 to 300 microns. 
     
     
       78. A method of conducting a chemical reaction in a chemical reactor, comprising: 
       passing a first gaseous reactant into a first compartment of a reaction chamber;  
       passing a second gaseous reactant into a second compartment of a reaction chamber;  
       wherein the first compartment has an internal volume wherein the internal volume has dimensions of compartment height, compartment width and compartment length;  
       wherein the second compartment has a second internal volume wherein the second internal volume has dimensions of compartment height, compartment width and compartment length;  
       wherein the second compartment comprises a compartment height or compartment width that is 2 mm or less, and further wherein the second compartment comprises a porous catalyst material;  
       wherein the reaction chamber comprises a wall that separates the first and second compartments and wherein orifices through the wall allow gas to flow from the first to the second compartment;  
       wherein the pressure in the first compartment is greater than the pressure in the second compartment; and  
       wherein the first gaseous reactant passes in a distributed fashion through the orifices through the wall and reacts in the second compartment with the second gaseous reactant along the length of the second compartment to form a product.  
     
     
       79. The method of  claim 78  wherein the chemical reaction is selected from the group consisting of: alkylation, dimerization, trimerization, epoxidation, dehydrogenation, oxidation, partial oxidation, and polymerization. 
     
     
       80. The method of  claim 79  wherein the reaction chamber comprises a bulk flow channel that is contiguous from the beginning to the end of the reaction chamber; and wherein the reaction chamber comprises a porous catalyst comprising an active constituent selected from the elements in the IUPAC Group IIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IVB, lanthanide series and actinide series. 
     
     
       81. The method of  claim 79  conducted in multiple reaction chambers that are connected in parallel, in series or both in parallel and in series. 
     
     
       82. The method of  claim 78  wherein the first compartment comprises a compartment height or compartment width that is 2 mm or less. 
     
     
       83. The method of  claim 78  wherein the second compartment comprises a bulk flow channel and the porous catalyst material has a porosity in the range of 30 to 98%. 
     
     
       84. The method of  claim 78  wherein the porous catalyst comprises a porous support with a catalytic metal thereon and comprising an active constituent selected from the elements in the IUPAC Group IIA, IVA, VA, VIA, VIIA, VIIIA, IB, IIB, IVB, lanthanide series and actinide series. 
     
     
       85. The method of  claim 84  wherein the bulk flow channel is contiguous from the beginning to the end of the reaction chamber and wherein the porous catalyst has a pore size of 0.1 μm to 200 μm, and wherein the first compartment comprises a compartment height or compartment width that is 2 mm or less. 
     
     
       86. The method of  claim 85  wherein the reaction chamber is in thermal contact with a microchannel heat exchanger and wherein the combination of reaction chamber and microchannel heat exchanger have a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       87. The method of  claim 78  wherein the second compartment comprises a porous catalyst having a pore volume of 5 to 98% wherein at least 20% of the material's pore volume is composed of pores in the size range of 0.1 to 300 μm. 
     
     
       88. The method of  claim 78  wherein the reaction in the second compartment is endothermic and wherein the reaction chamber is in thermal contact with a second reaction chamber in which an exothermic reaction is occurring and wherein the combination of the reaction chamber and the second reaction chamber have a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       89. The method of  claim 78  wherein the reaction in the second compartment is exothermic and wherein the reaction chamber is in thermal contact with a second reaction chamber in which an endothermic reaction is occurring and wherein the combination of the reaction chamber and the second reaction chamber have a heat flux of at least 0.6 W per cubic centimeter. 
     
     
       90. The method of  claim 78  wherein the chemical reaction is selected from the group consisting of: acetylation, amination, arylation, cyclooligomerization, dehalogenation, epoxidation, esterification, Fischer-Tropsch, halogenation, hydrohalogenation, hydrometallation, hydrosilation, hydrotreating (HDS/HDN), metathesis, nitration, polymerization, sulfonation, telomerization, transesterification, and trimerization. 
     
     
       91. The method of  claim 78  wherein the porous catalyst material insert has a pore volume of 30 to 95%; and wherein at least 50% of the pore volume is composed of pores in the size range of 0.1 to 300 microns. 
     
     
       92. A method of conducting a chemical reaction in a chemical reactor comprising: 
       passing a gaseous reactant into a first compartment of a reaction chamber;  
       wherein said reaction chamber comprises a porous catalyst material insert, a first compartment and a second compartment;  
       wherein said first compartment has an internal volume wherein said internal volume has dimensions of compartment height, compartment width and compartment length;  
       wherein said first compartment comprises a compartment height or compartment width that is about 2 mm or less;  
       wherein said porous catalyst material insert is disposed between said first compartment and said second compartment;  
       wherein the gaseous reactant reacts within the porous catalyst material to form at least one product; and  
       wherein said first compartment and said second compartment comprise open spaces that permit bulk flow of a gas.